DE 42 34 013 A1 discloses a hydraulic unit for a slip-controlled brake system, including a block-shaped accommodating member which, side by side in a first and second row of valves, comprises a total of eight valve-accommodating bore accommodating electromagnetically operable inlet and outlet valves. Disposed between the two rows of valves is a pump-accommodating bore, and two parallel accumulator-accommodating bores are arranged outside the rows of valves. The accumulator-accommodating bores are arranged transversely to the valve-accommodating bores directly adjacent to the second row of valves containing the outlet valve, while the pump-accommodating bore extends in parallel to the two rows of valves. Arranged centrally between the two rows of valves is a motor-accommodating bore that extends into the pump-accommodating bore paraxially relative to the valve-accommodating bores.
The disclosed hydraulic unit is appropriate exclusively for a slip-free braking operation and for being used for brake slip control.
Therefore, an object of the invention is to improve upon a hydraulic unit of the indicated type by simple means in such a fashion that an extension to traction slip control and driving dynamics control is possible, while the described arrangement of the bores in the accommodating member accommodating valves, pump and accumulator is maintained.
According to the invention, a third row of valves is provided opening into the first housing surface of the accommodating member between the housing plane provided for the ports of the braking pressure generator and the housing plane provided for the first row of valves. The third row of valves, which is thus arranged directly adjacent to the first row of valves, ensures a simple functional extension of the hydraulic unit designed for anti-lock control for the purpose of achieving traction slip control or driving dynamics control, to what end normally closed solenoid valves configured as electric change-over valves are inserted in the two outside valve-accommodating bores of the third row of valves. Separating valves in the form of solenoid valves open in their basic position are inserted into the two interposed valve-accommodating bores of the third row of valves.